Pipe connector



Sept. 12, 1950 J. c. RICHARDSON 2,522,194

`PIPE CONNECTOR Filed Deo. 14, 1946 lli i I N&\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\v I INVENTOR. Llame' Cf Richardson,

ATTORNEYS' Patented Sept. 12, 1950 UNITED STATES ATNT QFFHCE PEPE CONNECTOR Application December 14, 1946, Serial No. 716,370

3 Claims.

1 This invention relatestocoupling or connecting means for threadless pipe, tubing, conduit and the like, for connecting the same to other 4or similar structure in suchmanner as to obtain a leak-tight connection.

The need for convenient and satisfactory means for connecting ductile or bendable threadless pipe or tubing, e, g., of metals, such as aluminum, copper, lead, tin, zinc, iron,.and alloys of these metals, as well as of ductile plastic materials, topipe lines or to orices of structures such as engines, machines and commercial vor household fixtures, has been of long standing; one field of application for such connections lying in the use of -bendable threadless pipe'for connecting household fxtures, such as gas ranges and washing machines, which are to be semi-permanently installed, to existing pipe lines carrying'gas, water and the like.

Numerous proposals have been made in an attempt to satisfy this need. Most of these pro- ;posals involved couplingmeans for gripping `portions of the pipe walls, or clamping deformed portions thereof between opposed coupling member surfaces. Many of the couplings-heretofore `known were subject to disadvantages which impair their utility, or render theiruse unduly expensive or inconvenient. For example, in installations in which the coupling is subjected to axial or lateral stress, or to vibration,the connection tends to fail by gradual deformation of the portions of the pipe engaged by the coupling. Parts of the pipe subjected to the clamping or gripping action of the coupling members are often weakened thereby, rendering the pipe easily susceptible to fracture. vSome of the coupling means form constrictions or widened portions in thepassage extending through the coupling,-offering resistance to the flow of iiuids therethrough; and often junctions of several of the coupling members are exposed to fluids in the pipe, so that special precautions must be taken to avoid corrosion, particularly from electrolytic action when the junction is between dissimilar metals. Some of the couplings hereinbefore proposed require a large number of parts, whereby vparts thereof to make up the connection, constituting a considerable inconvenience, particularly ,in'massfproduction. Furthermore, .constructions 2 heretofore known are often subject to the'idisadvantage that .excessive force applied in making up the connection tends to weaken the pipe, while too little force fails to form a sufliciently tight joint.

In accordance with my invention, coupling means are provided for threadless `ductile pipe, tubing, conduit or other hollow tubular structures, hereinafter referred to as pipe, wherein only two interchangeable coupling parts are required to secure the pipe in leak-'tightengagement with another structure. These parts can be preassembled with the pipe, until used, vso that loss of the parts is readily avoided. The coupling is adapted to form a passageway of uniform diameter through the pipe and coupling, offering minimum resistance to the flow of fluids therethrough; .and only one junction between metal parts is necessarily exposed to the fluid in the pipe, so that corrosion problems presented by dissimilar metal junctions can be readily overcome. The parts of my coupling are simple in design, and can be readily economically made by mass production methods, The deformed portion of the pipe walls engaged by the coupling members is formed in such a manner as tominimize weakening of the pipe material, and the coupling members are arranged to 'clamp the pipe in such a manner as to avoid any tendency to weaken the parts of the pip-e engaged thereby. In consequence thereof, the-force applied in making up the connection is not critical, and the coupling can be tightened `with full force to/insure a leak-tight connection.

Furthermore, the number of turns required-for makingfup the coupling of my inventicncanfbe reduced to a minimum, consistent with the strength of the coupling members themselves. The coupling of my invention provides positive clamping force in axial direction, and in substantially right angles to the parts of the lpipe engaged thereto. Accordingly, the pipe islheld in such a manner as to crier maximum resistance to failure of the connection when subjected Vto vibration, or axial or lateral forces.

In accordance with my invention, I provide on or adjacent the end of the pipe an upset double-thickness flange, formed from the walls-of the pipe, and extending substantially in radial direction from the pipe. The upset flange can be made, as disclosed in my copending :application, Serial No. 702,026, of October 8, 1946, by subjecting an unconned short length of the pipe, at or adjacent the end thereof to compression in axial direction, while coniining adjacent portions of the pipe against expansion,

In accordance with this invention the compressing operation is performed on the end portion of the pipe. The unconned `portion of the pipe when subjected to compression, bulges outward to form a ridge or bead, and the two sides of the latter are then forced together to form a doublethickness substantially radial flange. Since the pipe wall upset Iby such compression is unconnned the metal of the pipe flexes or flows to form the flange in its most natural manner, thus avoiding substantial thinning, or weakening of the metal. At the base of the flange the metal is somewhat thickened and strengthened under the influence of the compression.

The upset flange is then clamped between a pair of coupling members, including drait means, such as inter-engaging threaded portions, whereby the coupling members can be forced together in axial direction of the pipe against opposite sides of the upset flange. The flange-engaging surfaces of the two coupling members are of shallow curved shape to conform substantially to the shape of the flange. Moreover the coupling members have telescoping portions adjoining the ilange-engaging surfaces cooperating therewith to form an annular chamber enclosing and substantially confining the flange. Thus, when the connection is made up and tightened with great force, the flange cannot become unduly deformed, and consequently weakened, by reason of the fact that the metal thereof is confined against sube stantial deformation by the walls of said annular space, The walls of said space are preferably constructed so as to diverge slightly in radial direction adjacent the bores of the coupling ineinbers, so as to prevent the material enclosed in the annular space from being forced inward toward the axis of the connection. Thus, the force applied in tightening the connection is not critical.

Opposite surfaces of the flange are clamped in leak-tight engagement with the coupling members, and the only joint exposed to the action of fluid within the pipe is that between one of the coupling members and the pipe itself,

Since the upset flange is the only part of the pipe forcibly engaged by the coupling members, and since their action on the flange requires no progressive wedging, the number of turns re quired to bring threaded coupling members into clamping engagement with the flange, can be reduced to a minimum. The clamping effect, being at right angles to a substantially rectangw lar flange offers maximum resistance to displacement of the pipe in the coupling, and to loosening by axial or lateral forces or by vibration applied thereto.

The coupling means of my invention is also adapted to provide a leak-tight joint between a pair of ductile pipe ends having similar upset flanges on the ends thereof, said flanges being compressed together in a conllning annular space by a pair of coupling members in the same manner as the flange on a single piece of pipe. Such use of the coupling requires no modification thereof, except that both coupling members have bores conforming to the outside diameter of the pipe.

Other features and advantages of my invention will appear from the following description of a number of preferred embodiments of my invention, illustrated in the accompanying drawings,

' wherein:

Figure 1 is an axial cross-sectional vfiew of the parts of a coupling in accordance with my invention, preassembled in preparation for making up the joint.

Fig. 2 is a side view, partly in axial cross-section, of the coupling of Fig. l, after the joint is made up.

Fig. 3 is a side view, partly in axial cross-section, of a modification of the coupling shown in Figs. l and 2.

Fig. 4 is a view in axial cross-section oi a pair oI" pipe ends connected by the coupling members of my invention.

Referring to Figs. 1 and 2 of the drawings, a piece of ductile pipe lil, to be connected to the mouth of a passage II, in a structure I2, has doubleewalled upset flange i3, formed at the end of the pipe. The upset flange can be formed, for example, by the method disclosed in my copending application, Serial No. 702,626, of October S, 1946, wherein the pipe is gripped by an encircling and confining die along a substantial length thereof, with an end portion of the pipe, of sufficient length to form an upset flange, protruding unconilned from the end of the die. The protruding end of the pipe is then subjected to compression in axial direction, for example, by supporting the end of the pipe against a compression member and forcing the die, together with the pipe enclosed therein, toward the compression member. The walls of the unconilned protruding end portion of the pipe bulge outward to form a bead, and the walls of the bead are then forced together to form a double-walled flange, extending substantially in radial direction from the pipe, To avoid reduction of the in ternal diameter of the pipe at the base of the upset flange, a mandrel may extend into the pipe from the open end thereof during application of compression thereto.

As shown in the drawing, the upset flange bearing pipe has a female coupling member Ill, the exterior of which may be advantageously shaped to engage a wrench, for example, by making its surface hexagonal or square. The coupling member I4 encircles the pipe I behind the upset flange I3, and has a sleeve portion I5 at its rear end with a bore conforming substantially to the outside diameter of the pipe. At its forward end, coupling member Ill has an enlarged cavity i6, of sufficient diameter to receive the upset flange I3. The outer portion of the cavity it is provided with internal threads Il. Extending inn ward from the threads Il the cavity I has a substantially cylindrical wall IS of the same, or slightly larger diameter, than the flange I3. The cylindrical portion of the cavity terminates at a shoulder I9, which preferably joins the bore of the sleeve I5 at a slightly (i. e. of small radius) rounded corner 20.

The shoulder I9 faces substantially in axial direction, but is made of concave cross-sectional shape, as by forming a shallow annular groove on its surface to make it conform substantially to the rear surface of the upset flange I3. The curvature of said groove preferably merges into the cylindrical portion i8 of the cavity. By reason of the concaved cross-sectional shape of the shoulder I9, the cavity I il has, in effect, a slightly re-emergent annular portion surrounding the mouth of the bore of the sleeve I5, so that its wall diverges slightly (e. g. by an angle of about ten to twenty degrees) in radial direction from a plane at right angles to the axis of the coupling, adjacent the bore of the coupling member.

The opposite coupling member of Figs.. l and 2 -lrfi's axbody,` or fitting 2 I having for. example, a pipeithreaded portion. 22 for Vengaging a correspondinglythreaded orifice in the mouth of the passage J kI I 'offstructure I2, and advantageously includes a nutV portion 23 of conventional hexagonal or square shape, for engaging a wrench. The body 2l has a bore 2li, of a diameter corresponding to thelinternal diameterof the pipe I0, and preferably ofthe passage II.

The opposite projecting end of the body 2| :.constitutes a male coupling member, adapted to f., cooperate `with the female member I4. ...adjacent the projecting end, it is provided with external .threads 25 for engaging the internal threads I'i of the member I4. Extending outward :..from theithreadsxit has a substantially cylindrical Thus,

portion 25 shaped to fit telescopically into the `.cylindrical portion I3 `of the coupling member Ill. `The end surface 27 of the body 2I is hollowed out,.as shown, to provide a shallow cup-shaped s. portion for engaging the outer end of the flange ,I3, and isadvantageously made with a shallow annular groove forming a slightly re-emergent end surrounding the bore 24, the shape of surface 21 being similar to the corresponding surface i of the shoulder I9 on the opposite coupling mem- 1 ber,` being thus adapted to flt the end surface of flange I3. The surface 2l, like shoulder I9, di-

verges slightly from a plane at right angles to the .-axis ofthe coupling, adjacent the bore' 24, sol .f that saidsurface and shoulder define an annular chamber for enclosing and confining the upset flange I3, the walls of said chamber diverging from each other in radial direction, adjacent the bore of the coupling by an angle of the order y of twenty to forty degrees.

When the coupling is made up, the upset flange v I3 at the end of pipe `It is seated against the cupshaped end 2l of the body 2l, and female 'couy pling member I4 is threaded on to the project.

ing end portion of the body until shoulder I9 at f the base of the cavity engages the rear side of the upset flange I3. When the parts are in this position, the cylindrical portion 26 of the body 2l has entered the cylindrical portion I8 of the cavity f I6, thus substantially conining the flange I3 within an annularspace formed by the end surface 21 of the body 2l, and the shoulder I3 at the Vbase of thecavity I6. The walls of said cavity diverge slightly in radial direction, adjacent the -bores of said coupling members.

Thus, when the two members are further tightened, the vre-emergent portions 0f shoulder I9 and surface 2l clamp against the opposite sides of the upset flange I3, and tend to force the metal of the latter outward in radial direction so that it will substantially fill the annular space. .the surfaces of the coupling members forming -said annular space conform substantially to the Since shape of the angei3, only slight deformation occurs. The inner edge 29 of shoulder I9 is swaged into the flange I3 but does not bite into `the-material thereof by reason of its rounded shape. :.:tightening the connection cannot injure the Exceedingly great force applied in ange I3, nor the pipe, since the metal thereof is confined within the aforesaid annular space, while -1 the slightly divergent walls of the annular space .p prevent inward flow of the material of the pipe or 2 flange. Thus, the joint can be tightened to any #desired extent without injury to the connection. An exceedingly tight joint can be formed in this way `between the contiguous surfaces of the body y 2 I. andLflangeIS, which eifectively prevents leak- .,agebetween the two. ,The yonly'junctrm exposed body 2| and the flange I3, so that by making; or lining the body 2I with the same metalv as the pipe IIJ, electrolytic corrosion can be avoided.

The bore of the body 2l being 'the same as the internal diameter of the pipe, provides a passage through the coupling of uniform diameter, oifering minimum resistance to passage of fluids through the connection. Since the relative movement of member It and body 2l from the point at which flange I3 is initially engaged by shoulder I9 and surface 2l, to the point at which the joint is fully tightened, is very slight, the extent of the threads Il and 25 may be reduced as far as consistent with the strength of the material of which the coupling members are made, so that a minilnum number of turns is required for making up the connection.

A modication of the connection of Figs. 1 and 2 is illustrated in Fig. 3. Essentially, the difference lies in the reversal of the male and female coupling members. Thus, in the construction of Fig. 3, the female coupling member 28 is provided with a threaded portion 29 on its rear end for engaging corresponding threads in the mouth of a passage in the structure I2a. The member 2% has a bore 3i), corresponding in diameter to the internal diameter of the pipe lila. The eX- ternal surface of the member 28 is advantageously made hexagonal, or of any other conventional shape to engage awrench. At its opposite end, the female member 23 has a cavity with internal threads 3 i, extending inward from its mouth, and a short cylindrical portion 32 extending inwardly from the threads, said cylindrical portion terminating at a shallow concave shoulder 33, similar in shape to the end surface 21 of the body 2I of Figs. 1 and 2, and adapted to engage the end surface of the upset flange I3a at the end of the length of ductile pipe Illa.

A male member 3ft isfprovided, having a bore conforming to the outside diameter of the pipe lila, and encircling the latter behind flange i3d. The male member 3S has a nut portion 35 and external threads 33 for engaging the threads 3| of female member The forward end of the member 35i has a cylindrical portion 3l, adapted to enter and telescopically fit the cylindrical wall 32 at the inner end of the cavity of member 28. The leading end surfaces 33 of coupling member (ill has a shallow concave shape joining ,the bore of member 3d at a rounded corner 33, and is thus similar in shape to the shoulder I9 of Figs. l and 2.

Thus, the shoulder 33 of female member` 28, and the end surface 35 of male member 361, are adapted, when the two are threaded together to form an annular space conforming substantially to the shape of the ange i3d, and to confine the same, said space having opposite walls, diverging slightly in radial direction adjacent the bores of said members.

In assembling the coupling of Fig. 3, pipel Ia is inserted into the cavity of female member 28 until it engages the shoulder 33 and male member is then threaded into said cavity until its leading end surface 33 engages the rearv side of flange 3a. When the members are in this posiv tion, as shown in Fig. 3, the cylindrical portion 3l of member. 3f has entered the cylindrical portion 32 hase of the cavity' of niem- 7 gently outward to ll said annular space, in which it is confined in the same manner as in the coupling shown in Figs. l and 2.

Provision of the rounded corner 39 for engag ing the rear of the flange i3d, where it .joins the pipe, avoids any tendency of member 34 to cut into the pipe, while at the same time clamping the fiange in such a manner as to form a leaktight connection between the flange and the shoulder 33 of member 28. As in the construe'- tion of Figs. l and 2, the passage through the pipe and member 28 is of uniform diameter, and only a single metal junction is formed between member 28 and flange 3a exposed to the fluids within the coupling.

Fig. fi illustrates the use of my coupling means for joining a pair of pipe ends, each having upset flanges as provided in the foregoing construe-- tions. Such use of the coupling involves provision of a pair of members, corresponding to fcmale coupling member lli of Figs. l and 2, and male coupling member 3dof 3. In this form of coupling a pair of ductile pipes lilb and llc are provided, having upset double-thickness flanges 3b and lc on the ends thereof, said pipes preferably having the same diameter. The pipe llb is encircled by a female coupling member lllb substantially similar' in every respect to the member le described above. Thus, it has a rearwardly extending sleeve l 5b, with a bore conforming to the outside diameter of pipe lib, and cavity leb, with internal threads ll'b, extending inward from its mouth; and a cylindrical portion |859 extending inwardly from threads, and joining a shallow concave shoulder Mb, adapted to fit l the rear surface of the flange 53D; said shoulder joining the bore of the sleeve l at a rounded corner 2gb of small radius.

The pipe lilc is encircled by a male coupling member 34C, having a nut portion 35e, external threads 33C and a cylindrical end portion Sie -adapted to enter and nt the cylindrical portion Sb of the cavity leb in member lill). The end surface 38e of the member Sflc is shaped like the .corresponding end of member .triin Fig. 3, being of cup-shaped, shallow, concave contour and having a slightly :ce-emergent projection where it joins the bore of member 3de. The corner therefor is likewise rounded, as indicated at 3de.

Thus, when the member Eile is threaded into f member hib, cylindrical portion 3'lc enters the cylindrical part SBD of cavity Ebb, and the end surface 33e of member flllc, and shoulder 59h of member llb form an annular space corresponding substantially to the external shape of flanges l3b and Eic when the latter are in abuttingl relation.

In making up the joint, the two members positioned on pipes lllb and lilo behind flanges isb and i3c, are threaded together, bringing the flanges into abutting relation, and confining them within the annular space formed, as stated above, by the end surface ll'lc and shoulder iii) of the two coupling members. As the members are tightened, the flanges are compressed together, and at the same time confined within the annular space, the metal thereof being forced gently outward to fill such space, by reason of the radially diverging walls of annular space. A connection is thus formed, wherein the internal diameter is uniform through the abutting pipes fEb ille, as in the case oi le preceding Variations can be made in the constructions herein illustrated without departing from the scope of my invention. Thus, the outer edge of the end surface of the male coupling member can be narrowed to a feather edge as illustrated, or made with a narrow annular end surface. In each of the illustrated constructions, the doublewalled flanges are formed in the preferred manner by upsetting the end portion of the pipe wall. If desired, however, the upset flange may be formed at a point spaced somewhat from the end of the pipe, the pipe end thereby projecting into the bore of the opposite coupling member. This, however, modifies the diameter of the passage through the coupling, and is accordingly used only where variations in the internal diameter are of no consequence.

The flange formed on the end of the pipe provides means whereby the coupling members can be preassembled therewith, so that the parts will not be lost priorfto use of the coupling to form a connection. From time to time, the coupling can be dismantled after it has been made up, and then reinstalled without impairing the tightness of the joint formed thereby.

Variations and modifications may be made within the scope of the invention, and portions of the improvements may be used without others.

I claim:

l. A coupling for ductile threadless pipe having an upset double-thickness flange formed from the wall of the pipe and extending radially outward therefrom, comprising a coupling member having a cavity for receiving said upset flange on the pipe, and a concave flange-engaging sur face at the bottom of said cavity, a second coupling member having a concave flange-engaging surface formed on a projection arranged to telescope within said cavity to provide an annular fiange-enclosing and confining space between said members and having outwardly diverging walls adjacent the base of the flange and a peripheral confining wall adjacent the periphery of the ange so proportioned that when said coupling members are drawn together said surfaces clamp said flange to form a leak-tight connection therewith, while the material of said flange is caused to substantially lill said recess and be compressed therein between said concave flange-engaging surfaces, whereby the approach of said coupling members is limited by the material of said flange lling said recess, and cutting of the fiange by said coupling members is prevented.

2. A coupling comprising a length of ductile threadless pipe, having at the end thereof a double-thickness upset flange formed from the walls of the pipe, and extending in radial direction therefrom, a coupling member encircling the pipe behind said flange, and having a shallow concave ange-engaging surface shaped to conform substantially to the rear surface of said flange; a second coupling member having threaded engagement with the first member operative to move said members relatively in axial direction; a bore in said second member coaxial with the bore of the pipe; and a shallow concave flange-engaging surface on said second member shaped to conform substantially to the front surface of said flange, said coupling members having portions adjacent the flange-engaging surfaces thereof in telescopic engagement so as to form with said flange-engaging surfaces a limited annular space for enclosing and confining said flange, said members when threaded to gether clamping and confining said ange in leaktight engagement therewith,

3. A coupling for ductile threadless pipe having an upset double-thickness ange formed from the wall of the pipe and extending radially outward therefrom, comprising a coupling member having a cavity for receiving said upsetA flange on the pipe, and a flange-engaging surface at the bottom of said cavity, a second coupling member having a flange-engaging surface formed on a projection arranged to telescope Within said cavity, said ange-engaging surfaces forming an annular ange-enclosing and confining space between said members having outwardly diverging walls adjacent the base of the ange and a peripheral conning wall adjacent the periphery of the flange so proportioned that when said coupling members are drawn together said surfaces clamp said fiange to form a leaktight connection therewith While the material of said ange is caused to substantially fill said recess and be compressed therein between said ange-engaging surfaces, whereby the approach of said coupling members is limited by the material of said ange filling said recess, and cutting of the ange by said coupling members is prevented.

JAMES C. RICHARDSON.

REFERENCES CITED The following references are of record in the 

